Fowlow on from "firing pot"

[underdog]

Hi all ok s400 as had her seals renewed and the firing pot/valve spring and firing valve all were brand new and set up as per post to 57mm also her air
Cylinder as been polished inside by a friend who had
A polisher bit welded to a drill bit he uses it for polising us springer cylinders well he gave me mine back yesterday and the inside of my s400 air cylinder is like glass now.The air in s400 was filled up to
130 bar over night and no leaks so far.
Now for setting up the power I'm doing it with Bisley 177 maguns as per post from Raj and Mark as post below.

Hi,

JSB Heavies (Daystate Heavies also I believe) at 10.3 grains are a good pellet to set power levels with. I would set it to 715 fps maximum (11.65 ft.lbs) to give a bit of legal clearance and you will be ok with Diablos which should be around 11.2-11.3 ft.lbs. If you are using Bisley Magnums then I would set to 11.5 ft.lbs (700 fps or a shade under) You may want to look at this thread viewtopic.php?f=15&t=2942 for a bit of light reading also You should get around 65 shots in a 11 fps sweet spot (1.5% of max velocity) dependant on pellet.

Don't think anti-tamper was around in 2006 (not with two of mine anyway) so DIY servicing is pretty straightforward.

Mark
S410C .177 Regged - MTC Viper 4-16 x 50
S410K .177 - Hawke Nite-Eye 4-16 x 50 AO IR
S410K .22 - Hawke Sport HD 3-9 x 50 AO IR
Logun Mk1 .22 - AGS 3-9 x 40
Theoben Taunus .22 - Simmons ProHunter 4-12 x 40 AO
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Walther CP99
Webley Premier .22
Mark112

Posts: 139
Joined: Mon Feb 16, 2015 5:25 pm
Location: Coventry
I'll let the forum know how I'm getting on with the power it may help other guys out
Thanks for reading post
ATB from Frank in kent

[Mark112]

Looking good then. Nice to have feedback on your project as it can indeed help others and do let us know how you get on once it's all done. If you do a full shotstring when power is set I'll post a graph of the results up. It also means you can see the optimum fill point to get to the 'sweet spot'. My .22 S410 which had a poor firing valve became more accurate as well as giving a flatter power curve which I wasn't expecting!

[underdog]

Thanks Mark that's very kind of you to do a graph would like that a lot thanks
Just a couple of questions for you all
When filling a Air Arms S400 up with air when completely empty I think you have to cocked the bolt prier to filling is this right ?
Also do I have to cocked the bolt as well when just topping up with air?
This question for Mark when I do the string do I fill up to 190 bar and at what bar or number shot do you want me to stop the string.And should I use those bisley 177 magnum or my JSB 177 /8.44 ?
I'll try and do the string this week
Thanks from Frank

[eboswan]

Thanks Mark that's very kind of you to do a graph would like that a lot thanks
Just a couple of questions for you all
When filling a Air Arms S400 up with air when completely empty I think you have to cocked the bolt prier to filling is this right ?yes
Also do I have to cocked the bolt as well when just topping up with air? only if you are well down on pressure
This question for Mark when I do the string do I fill up to 190 bar and at what bar or number shot do you want me to stop the string.And should I use those bisley 177 magnum or my JSB 177 /8.44 ?
I'll try and do the string this week
Thanks from Frank

[Mark112]

This question for Mark when I do the string do I fill up to 190 bar and at what bar or number shot do you want me to stop the string.And should I use those bisley 177 magnum or my JSB 177 /8.44 ?
I'll try and do the string this week
Thanks from Frank

Hi,
Sorry for the slow response but been in Birmingham on a booze cruise
I stop the string when the velocity has dropped back down to the same as you started with at 190 bar. When done reconnect to the fill cylinder and make a note of the end pressure as well. I prefer results in the plain form:

700
702
705
703
etc

... and obviously tell me what pellets you are using As for which pellets I would probably use the ones you are most likely to be shooting mostly with. Although you have used Magnums to set up the rifle the graph is probably of most use with the JSB's. You could do both of course.

Mark